
Front: Government of India above, in Devanagari and English, with the denomination spelled out in Hindi — एक रुपया — set in a dense floral medallion at the centre. At the right, a large rendering of the hexagonal one-rupee coin bearing the Lion Capital of Ashoka and the motto सत्यमेव जयते, the state emblem standing in for any portrait. Signed by Bimal Jalan as Finance Secretary. Serial 93D 889945, with an inset letter B.
Back: The reverse is the one that collectors remember: an offshore drilling platform at sea, derricks and flare stacks crowded over the water — the Bombay High oil field, the pride of India's energy programme in the period. Top left, the reverse of the one-rupee coin dated 1990 within sheaves of wheat, and beside it the value panel in the country's other official languages.
A Government of India note rather than a Reserve Bank issue, this coin-and-oil-rig design ran through the late 1980s and early 1990s; the signature and the 1990 coin date place this piece firmly in that window. Printing of the one-rupee note was given up in the mid-1990s, the coin taking over entirely until notes briefly returned in 2015.